This invention relates generally to panels for insulating and protecting walls and roofs and especially to laminated panels of foamed polymeric material. Panels of this type have proven to be effective. However to provide the desired surface strength with a low density foam, rigid plates or other protective layers have been required to resist deformation or damage to the panel. Also there has been a problem in preventing bowing or curling of the layers due to the variations in expansion and contraction of the weathering material and foam under the extreme temperature differentials to which these panels are subjected, especially when used for roofing.